TLDR; Porn damages the male brain in a particularly nasty and insidious way. It can and has ruined whole swathes of men and boys.
So I'm 26 and I've been watching online pornography and masturbating every day (sometimes multiple times) since I was about 13 and only in the last couple of months did I realise that porn is harmful and addictive.
For years I thought I was just suffering from depression and anxiety. Living life thinking I was just an introverted person who wasn't very sociable. It was so hard managing life on my own, I thought that was just normal and that everyone else was just better at dealing with life, I believed there was just something inherently wrong with me.
I feel foolish looking back, but no one ever told me it was bad and my peers certainly made it seem normal. Both in real life and online I saw men joking about porn use. I look back at those interactions and memes with sadness now.
Evolution did not prepare us for porn. Your brain thinks masturbating to porn is successfully mating with a new females and rewards you as such. This is the most powerful natural dopamine hit you can get. Now thanks to the internet you can engage with unlimited new mates pretty much when and wherever you want. It's hyper stimulation to the brain. This makes three major things happen to the brain over time. 1) Your reward circuitry becomes hypersensitive to porn, needing only a thought to start craving it. 2) That same circuitry becomes desensitized to everything else. Everything that should feel rewarding in life like hard work, excercise and most productive activity doesn't.
3) Perhaps most tragic is the effect on the pre-frontal cortex. This is the part of the brain responsible for 'executive control' (Abstract thinking, motivation for goal-directed activity, planning and problem solving, inhibiting impules, Flexibility/Openess, weighing consequences of actions). It's called 'hypofrontality' but essentially the constant dopamine from the reward center causes the pre-frontal cortex to become deficient.
It's been over two months since I quit using porn entirely. As soon as I found out what it was doing to me, why I was struggling with life it was an easy decision. I'm already feeling amazing, my friends, family and partner all day I seem like a new man, I'm more open, talking about my anxieties and getting strong. It's very painful looking back at all that time I struggled with life never knowing I could have taken control of it, but it's never too late to stop and see the potential of life. My depression has almost entirely lifted, my anxiety definitely spiked during my withdrawal and it was severe but meditation, excercise and the support of my loved ones got me through it. I also don't mind telling you I've had the best sex I've ever had with my partner in recent weeks. Now I'm just rebuilding my life from the rubble but I'm full of hope.
Any men out there, if you use porn regularly please think about stopping, your brain will thank you and you will thank yourself.